Machine for making electrical cables



ATTORNEYS I INVE m H. A. STAPLES MACHINE FOR MAKING ELECTRICAL CABLESOrlglnal Flled Aprll 23, 1952 Feb. 18, 1936.

Patented Feb. 18, 1936 PNT" FFlCE.

MACHINE roa MAKING memos!- CABLES Horace A. Staples, PlainfleliL N.J.,.assignor to Habirshaw Cable and Wire Corporation, New York, N. Y., acorporation oi New York Original application April 23, 1932, Serial No.

607,063. Divided and this application October '6, 1932, Serial No-636394 3 Claims. (Cl. 207-9) vision was made for minimizing thepossibility of 15 the introduction of undesired oxide into the sheath ofa metal cable as the same is formed from successive metal charges in anextrusion press.

The present invention has for its object the 20 provision of an improvedmachine for making a metal sheathed cable wherein provision is made forintroducing a special atmosphere such as a reducing or inert gas intothe extrusion press below the ram as the ram is withdrawn, which specialgas atmosphere prevents the formation of undesirable oxide upon the topsurface of the preceding metal charge and which special gas atmosphereis also maintained in the metal press during the recharging of the presswith a new 30 metal charge so that oxide formation'upon the surfaceof orin the new lead charge is also precluded.

A further object of the present invention resides in the provision of animproved machine for making electrical cables wherein provision is madefor introducing an inert or reducing gas into the press chamber whenthe'ram is being withjrawn and for maintaining such gas atmosphere inthe chamber during the recharging of the press.

A further object of the present invention resides in the provision ofanimproved machine with provisions for lubricating a lead press prior to acharging operation whereby subsequent extrusion operations arefacilitated.

A futher object of the present invention resides in the provision of animproved machine for making lead sheath cable wherein a reducing orinert gas atmosphere together with a quantity of a lubricating mediummay be introduced into the lead press cylinder prior to the introductionof a new charge of lead therein, which atmosphere and lubricating mediumcooperate to prevent the formation of undesired oxide upon 55 the leadin the cylinder and which lubricating medium also serves to lubricatethe walls of the cylinder to facilitate the subsequent extrudingoperation.

Further and other objects of the present incompanying specification andclaims and shown in the drawing, which by way of illustration shows whatI now consider to be a preferred embodiment of the invention.

The drawing shows in- Figure 1 the improved machine by which the presentimproved method of making a lead sheath cable is carried out; and 4 Fig.2 shows a slightly modified construction Of ram.

The customary process of applying a lead sheath to a cable comprises thepassing of the cable 10 through a closely fitting die H which almostabuts, another die I2 of a diameter slightly greater than that of thecable. Lead in a hot but solid form is pressed into the'space 'M betweenthe two dies and thence into the cylindrical space I dbetween'the cableand the inside of the larger diameter die. The pressure for extrudingthe lead sheath is obtained by a hydraulic rain Id which presses upon alead charge l! in the cylinder or lead press chamber l8.

Due to the large amount of lead which has to be used, particularly for acable of even normal length, it is generally impracticable to performthe extruding operation continuously. It is necessary to stop andrecharge the cylinder l8 from time to time and during these rechargingoperaperfect cables are produced.

In order to prevent the formation of the undesirable oxide, whichsubsequently becomes introduced into the lead sheath of the cable duringthe extruding operations, the previous procedure ismodified as will nowbe described.

The ram it is provided with a dummy head 22 carried on a stud 23slidably fitting'the head of the ram it. The stud 23 is interiorlyhollowed out as indicated at, 2t and from this hollowed out passage inthe stud ports or passages 25 extend laterally as shown. The interior ofthe ram is also provided with a hollowed portion or conduit 28.Connected to the upper portion of the ram and in communication with theconduit portion 25 is a flexible connection 21 which eirtends to athree-way valve generally designated 28. Beyond the three-way valve 28is an atomizing device 29 for atomizing a lubricating medium 5 such asoil which is taken into the atomizing device 29 from a reservoir-.30. 3!is a pipe or conduit throughwhich a reducing or other inert gas such asilluminating gas, carbon dioxide, steam or the like is supplied. underpressure. Such gas 613% surface is substantially at the bottom of thecylinder l8. With the rain in lower position, the three-way valve 28 isthrown to a position to admit a mist of lubricating oil and the reducingor other inert gas through the flexible. conduit 21 into the interior ofthe ram. The ram is then raised and the mist of oil and reducing gas issprayed on the walls of the chamber or lead press cylinder as the ram iswithdrawn upwardly. It will be understood that the dummy head 22 on theram drops and allows the mist to flow laterally to the walls between theupper part of the ,dummy head and the lower part of the plunger arm. Thegas and lubricating medium passes around the dummy head and down intothe space between the top of the previous lead charge and the ram, asthe ram is withdrawn upwardly. In this way a reducing atmosphere orinert gas atmosphere is maintained inthe chamber or space above the oldlead charge between the upper surface thereof and the ram as the ram isbeing withdrawn. The lubricating medium sprays the bore of the leadpress with oil, preventing sticking of the ram and facilitating thesubsequent extruding operation.

The next step in the operation is to fill the chamber of the metal presscylinder or container with a new charge of metal such as lead. Suchmetal, for example molten lead, is introducedinto the chamber orcontainer of the extrusion press through a removable pipe 32 which leadsto a-lead pot or lead pump or other source of metal supply. The pipe 32during the filling operation, is extended down into the special atmosphere in the container. After filling such pipe 32 is removed. Duringthis filling operationthe three-way valve 28 is shifted to a position toshut off further supply .of gas and lubricating medium and to establishcommunication between conduit 21 and a pipe 33 so that upon subsequentlowering of the ram, gas can escape from the press chamber through theram to the atmosphere. Pipe 33 may extend directly to atmosphere or itcan extend into a water seal indicated by dotted lines at 34. The leadis then introducedinto the press chamber within press cylinder I8 andthe reducing gas atmosphere is gradually displaced and dischargedthrough pipe 33. During. the filling operation it will be appreciatedthat the reducing gas or other inert atmosphere within the chamber l8prevents oxidation of the lead either in the new lead charge, which isintroduced in a molten state, or upon the top surface of the old leadcharge I I.

The machine is then ready for the subsequent extruding operation. Duringthe extruding operation the three-way valve is shifted to closedposition and extrusion proceeds in the usual manner.

By the above procedure oxygen is prevented from reaching the surface ofthe old lead charge or the molten lead while such lead is beingintroduced into chamber l8. The reducing gas or inert gas which wasintroduced in the chamber or cylinder of the lead press upon upwardwithdrawal of the ram prevents oxygen from the air from entering thechamber and precludes oxide formation.

Furthermore the lubricating medium supplements the reducing or inert gasupon being highly heated since such lubricating medium under heat itselfbecomes converted into hydro-carbon gas which has reducingcharacteristics.

Figure 2 shows a modified form of ram. With this form the supplementalor dummy head 22 is dispensed with and in lieu thereof the ram lea is soshaped that its lower integral portion constitutes the head. An interiorconduit 26a is provided as before and openings or passages 25a extend tothe periphery of the ram. Preferably a closing plug 40 is provided inthe lower face of the ram I6a. With this construction the gas which issupplied under pressure to conduit 26a escapes into the space below theram upon withdrawal of the ram by passing from passages Na around theedges of the lower end of the ram. The diameter of the lower end of theram permits such gas flow. With the construction shown in Fig. 1 thediameter of the supplemental or dummy head is such as to provide forsuch gas flow upon upward withdrawal of the ram.

The present application constitutes a division of my copendingapplication Serial No. 607,063, filed April 23, 1932, for Methods andmachines for making lead sheathed cable." The method herein set forth isclaimed in the aforesaid parent application, Serial No. 607,063.

What I claim is:

l. A machine for making a metal sheathed cable and comprising incombination, a chamber for receiving heated metal and from which thesheath is adapted to be extruded, a ram cooperable with said chamber forexerting pressure on metal therein, the said ram having an interiorpassage, a source of gas, and means for conducting a special gasatmosphere from said source and through said passage into said chamberduring the withdrawal of said ramwhereby air is excluded from saidchamber during extruding operations.

v 2. An extrusion press comprising in combination, a cylinder adapted toreceive heated metal and provided with outlet means for forming atubular sheath, a ram cooperable with said cylinder for forcing metaltherefrom through said outlet means, the said ram having an interiorpassage communicating with outlets at that portion of the ram whichenters the cylinder first, means comprising an extension head movablymounted on said ram for closing said last mentioned outlets when the ramis moving into the cylinder and through said passage into said chamberduring the withdrawal of said ram whereby air is excluded from saidchamber during extruding operations, and means for supplying lubricantto said special gas atmosphere and thereby causing the latter to carrythe lubricant into said chamber. HORACEA. STAPLES.

for opening-said last mentioned outlets when the

